Gyroscopic compass



G. A. ROSSITER.

GYROSCOPIC COMPASS.

APPLICATION FILED Nov. 13. 1919.

1,367,834. Patented Feb. 8,1921.

2 SHEETS-SHEET .l.

G. A. ROSSITER.

GYROSCOPIC COMPASS.

APPLICATION FILED Nov. 13. 1919.

1,367,834, Pawnt'ed Feb. 8, 1921.

2 SHEETSSHEET 2.

UNITED STATES GEORGE A. ROSSITER, 0F BROOKLYN, NEW YORK, ASSIGNOR TO THE CARRIE GYRO- SCOPIC CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

GYROSCOPIC COMPASS.

Specification of Letters Patent.

Patented Feb. 8, 1921.

Application filed November 13, 1919. Serial No. 337,651.

To all whomv it may concern:

Be it known that I, GEORGE A. RossIrER,-a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Gyroscopic Compasses; and I do hereby declare the followplify the construction and to increase the efiiciency of operation of certain of the instruments of this character by means which have not been .heretofore proposed.

lVith these and other objects in view the invention consists in the novel details of construction and combinations of parts more fully hereinafter disclosed and particularly pointed out in the claims.

Referring to the accompanying drawings forming a part of this specification, in which like numerals designate like parts in all the v1ews: Figure 1 is a diagrammatic vertical sectional view, partly in elevation, of one form of control compass made in accordance with this invention;

Fig. 2 is a horizontal sectional View, taken on the line 22 of Fig. 1, looking down in the direction of the arrow; and

Fig. 3 is a diagrammatic view illustrating a portion of the electric circuits used in this invention.

l designates the gyro wheel, journaled for rotation about its axis, 2, in the casing 3,

pivotally mounted in the vertical ring 4-on the trunnions 5. Y

Said vertical ring is pivotally mounted in the follow up, or shadow ring 6, by. means of the vertical pivots, or studs, 28 and 29, supported in the pivoted frame 52 having the depending vertically disposed member 7, as

shown.

' In order to suppress one of the degrees of freedom of the gyro wheel,- and thus secure orientation thereof, its axis 2 is located below the axis of the trunnions 5, as illustrated, and in order to dampen out the oscillationsof the north pointing end of axis 2, during said orientatioml provide the magnet 50, located on the shadow ring 6, and armature 51 located on the casing 3, all as will be readily understood from U. S. Pat- (15391? 1308693, to J. E. Beattie, datedJuly 1,

Said frame 52 is provided with the pivots 9 journaled in the inner ring 8, and at 90 from said pivots 9, said inner ring'is provided "with the pivots 10 journaled in the bearlngs 11, carried by the outer ring 12, supported from the binnacle casing 13 by the ball bearings 14 as shown.

Said binnacle casing 13 has secured thereto, as by the bracket 15, a motor 16 having a shaft 17, carrying the pinion 18, meshing PATIENT OFFICE.

with the circular rack gear 19, carried by the outer Cardan ring 12, so that when said motor 1s energized it will readily move said outer and inner rings as well as said frame 52 and vertically depending portions 7 ,in azimuth, for a purpose that will presently appear. Carried by the shadow ring 6 are a pair of brackets 20 and 21 respectively carrying the trolley contacts 22 and 23 adapted to respectively make circuit with the contacts 24 and 25, carried by the brackets 26 rigid with said vertically disposed portions 7 of the frame 52, as will be clear from the drawings.

The said trolley contacts 22 and 23 together with contacts 24 and 25 constitute a pair of reversing switches as will presently appear.

Carried by the main frame member 7 is another servo or follow up motor 30 adapted to drive through a gear train 31, the azimuth gear 32 secured to the follow up member 6. The function of the mechanism just disclosed is to always maintain the follow up member 6 substantially in the plane of the gyro wheel 1. as will be clear from my prior Patent #1311716, granted July 29, 1919, and entitled Gyroscopic compass.

I The said servo motor 30, as well as thefirst mentioned motor 16 is diagrammatically illustrated in Fig. 3, in which 40 indicates the armature of said servo motor 30 connected in series with a pair of oppositely wound field coils 41 and 42 adapted to be controlled by a relay 43, whereby the said field coils may be excited alternately to produce rotation of the armature 40, in one direction, and then in the opposite direction in the well known manner, as will appear morefully be low. The relay 43 comprises a pair of coils 45 and 46, one of which 45 is connected to an insulated metal contact member 47, while the other coil 46 is connected to another insufield coils of the motor 16, 63 another of said field coils, and 64 and 65 contacts adapted to coact with the trolley contacts 22 and 23 respectively.

The arrangement being as disclosed in Fig. 3, the operation of the motors and 16 will be as follows :-Current entering the lead wire 60will be conducted, through the wire 70, to the point 71 of the relay whence Supposing the contact 33 to make circuit with the contact 47, said current will traverse the coil '45., the wire-72, contacts 47, trolley contacts 33 and 34, the wires 73 and 74, the wire 75, and back to the return wire 61'as illustrated.

The energization of the coil 45 will make circuit between the contacts 76 and 77 of the relay 43, whereupon current from the wires 70 will reach the point 78 of relay 43, traverse said contacts 76 and 77, the wire 79, said coil 42 of motor 30, through the armature thereof, wire. 80 and wire 75 back to return wire 61.

The motor 30 will be thus reversed wh'ereupon the trolley contacts 33 and 34 will make circuit with their companion contacts 48 as will be understood. The making of the circuit through'the trolley contacts 33 and 34, and the contacts 48 will now permit current from the positive lead 60 to pass from point 71 through the coil 46, the wire 81, contacts 48, trolley contacts 34 and 33, and the wire 75 back to the return lead 61.

The energizing of the coil 46 now closes circuit between the contacts 82 and 83 of the relay 43 and permits current from the lead 60 and wire 70 to reach the point, 78, to cross the contacts 82 and 83. and to traverse the Wire 84, the filed coil 41 of motor 30,-the armature 40, and wire 80 back to wire 75 and negative lead 61.

The energizing of the field coil 41 will thus reverse the motor 30 and again, cause the trolley contacts 33 and 34 to make circuit with the contacts 47 in the manner well known. It thus will happen, as is fully disclosed in my said Patent #1311716, that the shadow ring 6 will always be kept substantially-in the same plane as the gyro wheel 1, even though the ship may be moving in azimuth. In the same way, the sec ond servo motor 16 will always maintain the vertical member 7 of the supporting frame 52 substantially in. the same plane as the shadow ring as will now be made clear. That is to say, since the shadow ring, through its trolley contacts 22 and 23 will always make circuit with their companion contacts 24, 25 or 64, 65. the motor 16 will act to automatically maintain said vertical member 7 in the plane of the shadow ring as will now be explained in detail. In other Words, supposing the trolley contacts 22 and 23'are respectively making circuit with their companion contacts 64 and 25. Current will now pass from the positive lead to the point 90, through wire 91 to the point 92, whereupon the current will divide and a portion thereof pass through the trolley contacts 23 and 25 to the wire 93, while another portion thereof will pass through the trolley contacts 22 and 64 to the wire 94, thence the two portions of the current will pass through the field coil 62 of motor 16, through said motor to the wire 95, and back to the negative lead 61. The energization of the field coil 62 will turn said motor 16. in such a direction asto cause the trolley contacts 22 and 23 to respectively make circuit with their companion contacts 24 and 65, whereupon current will now pass from the positive lead 60 through the wire '91 and said contacts 22 and 23 across to their respective companion contacts 24 and '65 and to the point 96, wire 97, field coil 63 and Wire 95 back to the negative lead 61.

- It will thus be seen that the second servo- 'motor 16 will be reversed as often as the trolley contacts 24 and 25 are moved in azimuth, and therefore, .the vertical portion 7 of the frame 52 will always be held in substantially the same plane as the shadow ring 6, and gyro wheel 1, as will likewise be readily understood from my Patent #1311716. The automatic maintaining of the supporting frame 7, in a fixed position, relatively'tothe gyro wheel, will of course,

also maintain all of the parts of the compass in relatively the same positions even though the ship may move in azimuth. In other language, supposing the axis 2 of the gyro Wheel is pointing north and south, and that the Wheel itself is in an east and west plane. The servo motor 30 will, in the manner above explained, maintain the shadow ring 6 in an east and west plane and although the ship may turn in azimuth and thus carry with it the binnacle casing, the outer and inner Cardan rings, as well as the supporting frame 52, yet, the servo motor 16 will, through the connections just disclosed, turn v the said frame 52 in a direction opposite to that in which the ship is turning and thus maintain all of the parts in their original relative positions notwithstandingthe ship may continue to turn in azimuth. The advantage of this invention may now be made clear from what follows: It is well known that when one builds a gyro compass, all of the parts must be accurately adjusted, balanced, etc., so that the rolling and pitching movements of the vessel Wlll not cause serious errors 1n a sea way.

It is further well known that it is an exceedingly difiicult matter, as well as a very expensive operation to so adjust the parts a sea way.

but-it will suffice to state that if we consider the wheel system consisting of the wheel 1, the axis 2, the casing 3,the pivots 5, etc., its center of gravity may be located at some point outside of the axis 2, and outside of a line passin through the verticalpivots 28 and 29. aid center of gravity, however, will be located in the vertical plane, for the action of gravity will bring it into said plane.

For the sake of clearness, let us suppose that the pivots 28 and 29 are not in a vertical plane, but are inclined to said plane and occupy some such exaggerated position as that indicated by the broken line 100. When the compass is tipped, let us further suppose for the sake of clearness, that the center of gravity of the wheel system is located at some point outside of the line 100 supposed to join the pivots 28 and 29, and at such an exaggerated point as that indicated at 101. In the same way, the center of gravity of the frame system, comprising the frame 52, the motor 30 and its associated parts may be, for the sake of clearness, considered to occupy some such exaggerated position as that indicated at 102, which is likewise well out of the line 100, supposed to cession. etc., certain errors in the indications of the compass card. But if the wheel 1. shadow ring 6. and frame member 7 are always maintained in the same plane as by the motors 30 and 16, these errors will be con tant for the same disturbing force, no matter how the ships head may change in azimuth.

In other words. the changing of the ship's course does not change the relations of the centers of gravity of the various systems, and therefore the same disturbing force will always produce the same errors. Accordingly. when the additional motor 16 and its connecting parts are provided as disclosed above. the manufacturer may without turning the binnacle 13 in azimuth subject the compass. to every disturbance it can be subjcctcd to in a sea wav: and he may then note the error for each disturbance and either allow for it or so adjust his balancing weights (not shown) as to substantially eliminate it.

Then when his binnacle is successively turned in azimuth, and his compass is subjected to the same set of disturbances he will note that his errors for each new heading or ships course have remained substantially constant. I

On the other hand, let us suppose no provision is made for maintaining the vertical member 7 in the plane of the shadow ring 6 and wheel 1. In such case the center of gravity 101 remains fixed as before, owing to the gyroscopic action of the wheel, but as the ship turns in azimuth, while the axis of the pivots 28 and 29 is tipped, and occupies the line 100 said turning movement will carry the center of gravity 102 of the frame system around said line as a center, so that for a fixed disturbing motion perpendicular to the plane of the paper, the leverage 103 will vary for each heading of the vessel.

It follows that in this second case, the two centers of gravity 101 and 102 will no longer exert the same combined disturbing force through friction, precession, etc.,- as in the first case, and that the errors engendered will furthermore vary for each heading, although the disturbing force be constant.

It is therefore apparent that the problem of the manufacturer in producing a successful gyro compass is much easier and less expensive when a second motor 16 is employed for he is relieved of a portion of the painstaking balancing and adjusting operations that he is forced to perform when only a single motor 30 is employed.

Of course, it will be understood that in practice the centers of gravity 101-and 102 are not liable to be located in the exact positions indicated, but the principles disclosed will control the operation no matter where they are located, provided substantially a mathematical adjustment is not had. It

will further be clear that in an exceedingly accurately balanced instrument such as a gyro compass, almost every part constitutes in some sense a system of its own, having inertia, momentum, etc. and that it is therefore very desirable, indeed, after an accurate balance has been once attained to keep this balance. Such a requirement is exceedingly difficult to comply with, when some of the parts remain fixed through gyroscopic action, and others move in azimuth with the ship. But when this last mentioned motion is suppressed, as by always maintaining the original relations between the parts whether they be the ones above considered, or not, the combined errors for different disturbances become substantially constant, and can be corrected for as a whole.

It is obvious that those skilled in the art may vary the details of construction as well as the arrangement of parts without departing from the spirit of my invention, and therefore, I do not wish to be limited to the porting said ring; and means for moving said ring and frame in azimuth relatively to said binnacle casing, substantially as described.

2. In a gyro compass provided with a binnacle casing the combination of a gyro wheel; a shadow ring; connections between said wheel and ring; a'supporting frame;

and means for automatically maintaining a' portion of said frame in the plane of said shadow ring, while said casing is moving in azimuth, substantially as described.

3. In a gyro compass having a binnacle casing the combination of a gyro wheel; a shadow ring; connections between said wheel and ring; a supporting frame in which said ring is mounted; a Cardan ring supporting said frame; and means for maintaining portions of said frame and'Cardan ring in the plane of said shadow ring while said casing is moving in azimuth, substantially as described. I

4. In a gyro compass the combination of a gyro wheel; a supportingirame; pivotal connections between said wheel and frame; a Cardan ring; connections between said ring and frame; a binnacle casing for supporting said ring; and means comprising a motor and electrical connections indirectly controlled by said wheel for moving said ring and frame in azimuth relatively to said binnacle casing, substantially as described.

5. In a gyro compass provided with a binnacle casing the combination of a gyro wheel; a shadow ring; connections between said wheel and ring;.a supporting frame; and means comprising a motor and electrical connections between said shadow ring and motor for automatically maintaining'a portion of said frame in the plane of said shadow ring, while said casing is moving in azimuth, substantially as described. 7

6. In a gyro compass provided with a binnacle casing the combination of a gyro wheel; a, shadow ring; connections between said wheel and ring; a supporting frame in which said ring is mounted; a Cardan rin'g supporting said frame; and means comprising a motor and electrical connections between said shadow ring and motor for maintaining portions of said. frame and Cardan ring in the plane of said shadow ring while said casing is moving in azimuth, substantially as described.

4 7. In a gyro compass the combination of a frame adapted to support the gyro wheel and 1ts assoclated parts; an inner Cardan ring supporting said frame; an outer Cardan rlng supporting said inner ring; a casing adapted to be moved in azimuth supporting saidputer ring; and means for automatically moving sald frame and inner ring in azimuth in a direction opposite t id i owhen said casing is moved in azimuth, s b? stantially as described.

8. In a gyro compass adapted for use on ships the combination of a gyro wheel; a caslng in which said wheel is mounted; a vertical ring in which said casing is pivoted; a shadow ring in which said vertical ring is supported, a follow up motor and connections adapted to maintain said shadow ring in the plane of'said wheel when the ship moves in azimuth; a supporting frame for said shadow ring; and a second motor and connections for maintaining a portion of said frame in the plane of said shadow ring when said ship moves in azimuth, substantially as described. 4

9. In a gyro compass the combination of a binnacle casmg; anouter Cardan ring supsupported by said inner ring; a motor carried by sald casmg and connections between said'motor and outer Cardan ringfor moving the latter as well as said inner ring and as described.

11. In a gyro compass for ships the combination of a binnacle casing; an outer Cardan ring; ball bearings between said ring and casing for movably supporting said frame relative to said casing, substantially ring; an inner Cardan supported by said outer ring; a frame pivotally supported by said inner ring: a follow up ring pivotally supported by said frame; a vertical ring carried by said follow up ring; a wheel casing carried by said vertical ring; a gyro wheel in said wheel casing; a motor and connections for maintaining said follow up ring in'the plane of Said wheel as the ship moves in azimuth; and means for also maintaining a portion of said frame in the plane of said 7 follow 11p ring while the ship is moving 1n azimuth. substantially as described.

In testimony whereof I aflix my signature.

GEORGE A. ROSSITER. 

